where to find an accessory / ignition wire under bonnet ?

[BillyGoatCountry]

I need to tap into a wire under the bonnet which is live when the engine is running so i can use it to activate a relay.

Many people will use the positive from the back of the ciggie lighter to do this but in my case it is already being used to operate a couple of other relays and i dont want to load it up too high.

Can someone suggest where else to tap into that wont load up other components ?


This leads me to another common issue with most vehicles , manufacturers probably didnt design them to take the massive numbers of accessories that aftermarket guys like to add.

Is there anyone providing a kit that is designed to add a power block with fuses to four wheel drives for accessories , which creates an independent circuit engineered safely so it wont load up OEM circuits ?

I am thinking of probably a heavy duty relay connected to the alternator with a timer so it cuts in a few seconds after engine start up , a main fuse and then 6 - 8 fuse blocks to connect accessories on to.

I might be wrong but i have the impression that most people tend to piggy back new loads on to existing circuits which to my thinking is a bit crapp... lol

[Bushwalker8]

I use this in my SR for the trailer fridge, it's simple: https://www.redarc.com.au/smart-start-sbi-12v-100a
Switches through after input voltage rises over 13.2V, e.g. engine (alternator) running, disengages after input voltage drops below 12.7V when engine stopped.

Otherwise for general accessories the Toyota accessory fuse block PZQ8589630 is designed exactly for this, it's pre-installed in many variants.

BTW the 12v outlets are active on the ACC position, not just when the engine is running. And in at least Gen 8 the dash 12v outlet(s) are fed by a special aluminium wire that is not compatible with any standard taps or connectors and will be damaged if you try. Assuming you can even access them, it's very tight in there.

[numberplate]

I couldnt find anything under the bonnet that was suitable , so i used the seat heater fuse , which is in the small fusebox to the left of the glovebox.

[BillyGoatCountry]

the Toyota accessory fuse block PZQ8589630 is designed exactly for this, it's pre-installed in many variants.

.

excellent thanks , i had no idea those were available and perfect for the job , cant understand though why my 2008 KUN26R doesnt have one since it was fitted up with mine spec electricals from new , having said that the electrical work was shitthouse and i stripped out some of it and did it again properly.

[Bushwalker8]

2008 KUN26R

Just checking, the part number I gave is for Gen 8 (2015-present) this section of the forum you posted?

[BillyGoatCountry]

2008 KUN26R

Just checking, the part number I gave is for Gen 8 (2015-present) this section of the forum you posted?

correct sorry mate , i didnt notice the post was 2015 >

Mods can move it if they like ?

Pardon I.

[BillyGoatCountry]

I couldnt find anything under the bonnet that was suitable , so i used the seat heater fuse , which is in the small fusebox to the left of the glovebox.

I put a voltmeter on that and timed it , it seems to be on a 5 second delay after the key is turned to ACC or engine started before it powers up.

It might suit some devices but I need almost immediate crossover to the relay so I will have to keep looking for a better option under the bonnet.

Thankyou.

[numberplate]

I put a voltmeter on that and timed it , it seems to be on a 5 second delay after the key is turned to ACC or engine started before it powers up.

thanks for letting me know , I had not noticed that before .

[Bushwalker8]

a better option

Yours is probably similar to gen 8 with very few options. Best & most reliable source I could find in mine was splice (solder) directly into the ACC wire off the ignition switch to trigger an additional relay I put in for the CB & extra 12v outlets behind rear seat & back in the tray (supplied from the previously mentioned fuse block).

It was an easy enough place to get at in the steering column but if you do make sure you use a vey low amperage inline fuse as close to the splice as possible so any issues won't take out the complete vehicle ACC supply.

[Myralga]

In both gen 7 and 8 it will be inside (in a gen 8 it’s under the glove box can’t remember in the 7 maybe steering column).
I use a piggy back jumper fuse into the cig power supply. That way your not interfering with the cig itself.
If your switching relays on and off your talking milliamperes thats stuff all in the overall scheme of things even if your talking 5-6 a 3amp fuse will handle that.


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[BillyGoatCountry]

In both gen 7 and 8 it will be inside (in a gen 8 it’s under the glove box can’t remember in the 7 maybe steering column).
I use a piggy back jumper fuse into the cig power supply. That way your not interfering with the cig itself.
If your switching relays on and off your talking milliamperes thats stuff all in the overall scheme of things even if your talking 5-6 a 3amp fuse will handle that.


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i run a dashcam from the ciggie lighter power , i noticed if i added one more load to it the dashcam was having too much voltage drop and it would switch itself off.

There is 3 - 4 items piggy backed on to the ciggie lighter already so if the dashcam wont run then i think it is overloaded enough.

There must be a circuit with spare capacity somewhere under the bonnet that is powered in ACC mode , the only testing i had time for so far is on the 8 x 4 inch box just behind the start battery but everything in there is permanently powered on .

There is the circuit that gives power to the fuel system but i dont want to touch that as it could create safety issues when driving if it blows a fuse.

[dave g]

I run a wire from the ignition through the firewall the battery and use that as a hotwire when I'm hooking up things it's only live when the ignition is turned on. it is fused at the ignition end and the accessories are fuse when I look at the other end of the wire I found that most of the wires in the car are too light to tap off or it ended up interfering with something else.